Comfort Relay Location W126

stwat

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Can anyone please tell me where the comfort relay is in an 89 300SE ?

The problem I am having is that the central locking does not work. I have tried two pumps and both are doing exactly the same thing. When i lock or unlock the car, all that seems to happen is one of the relays in the pump repeatedly clicks very faintly, Like I say, both pumps I have do the same. Also none of the windows open or close when you hold the key in the lock or unlock positions

I was wondering if it could be anything to do with the comfort relay. There is a while relay in the fusebox that feels quite warm to the touch and when I removed the fuse for the central locking it clicked ! Is that the comfort relay?

Thanks,

Stu
 

219

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Do W126's have comfort locking ?

Neither of mine do and I have never come across it . It was a feature I liked on my W124's and one that I would like to retrofit if it were possible .

It is not mentioned in my owners' handbook .
 
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stwat

stwat

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I have seen it mentioned on the fuse list under the fusebox lid. Sadly it didn't say which relay it was. :dk:
 
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stwat

stwat

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Hmmm. Just looked at my manual and you are correct Derek. No mention of comfort locking. But,,,,,,

,,,,looking at the fuse designations fuse number 2 has listed among with the clock, hazards, roof light, radio, vanity mirrors,,,,,,,,,'relay comfort circuitry terminal, 86.':dk:
 

franey

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its a real small part thaat can sometimes be hidden behind all the wires sat in the fuse board, measures about 10mm thick, 20mm wide, 30mm deep, look very carefully, its a little black number.
 
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stwat

stwat

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So I'm looking for a black maybe grey relay that is hidden away in the depths of the fuse box hidden by a maze of wires:doh: :crazy::D

Me thinks it's time to crack open the techinfo on line manual to study the wiring diagrams.

Oh joy !
 
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ianrandom

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It is one of the obvious relays in the fusebox aft of the fuses for sure but i cant remember which one. Its function is only to allow the electric windows to be operated when either of the front doors are ajar. Unfortunately it has no other frills. Still a useful little feature though.

If you open the front doors perhaps it will become warm and you can feel which one it is..
Does your car have any aftermarket alarm etc? They can have features like window closing etc but if you havent got one of those when it wont have it. Also, if you do have one of those perhaps that could be the cause of your problem with the locking. Cant think of anything else it could be, its a fairly simple system.

Each of the doors and the filler flap have little switches in the locks which reverse the current when switched, i believe. This is sensed by the pump which then triggers, and the vacuum is used to lock/unlock the doors.
 

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